<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>图片模态框</title>
  <style>
    #myImg {
      border-radius: 5px;
      cursor: pointer;
      transition: 0.3s;
    }

    #myImg:hover {opacity: 0.7;}

    /* The Modal (background) */
    .modal {
        display: none; /* Hidden by default */
        position: fixed; /* Stay in place */
        z-index: 1; /* Sit on top */
        padding-top: 100px; /* Location of the box */
        left: 0;
        top: 0;
        width: 100%; /* Full width */
        height: 100%; /* Full height */
        overflow: auto; /* Enable scroll if needed */
        background-color: rgb(0,0,0); /* Fallback color */
        background-color: rgba(0,0,0,0.9); /* Black w/ opacity */
    }

    /* Modal Content (image) */
    .modal-content {
        margin: auto;
        display: block;
        width: 80%;
        max-width: 700px;
    }

    /* Caption of Modal Image */
    #caption {
        margin: auto;
        display: block;
        width: 80%;
        max-width: 700px;
        text-align: center;
        color: #ccc;
        padding: 10px 0;
        height: 150px;
    }

    /* Add Animation */
    .modal-content, #caption {   
        animation-name: zoom;
        animation-duration: 0.6s;
    }

    @-webkit-keyframes zoom {
        from {-webkit-transform: scale(0)} 
        to {-webkit-transform: scale(1)}
    }

    @keyframes zoom {
        from {transform: scale(0.1)} 
        to {transform: scale(1)}
    }

    /* The Close Button */
    .close {
        position: absolute;
        top: 15px;
        right: 35px;
        color: #f1f1f1;
        font-size: 40px;
        font-weight: bold;
        transition: 0.3s;
    }

    .close:hover,
    .close:focus {
        color: #bbb;
        text-decoration: none;
        cursor: pointer;
        transform: rotate(360deg);
    }

    /* 100% Image Width on Smaller Screens */
    @media only screen and (max-width: 700px){
        .modal-content {
            width: 100%;
        }
    }
  </style>
</head>
<body>
  <h2>图片模态框</h2>
  <img id="myImg" src="http://www.runoob.com/wp-content/uploads/2016/04/img_lights.jpg" alt="Northern Lights, Norway" width="300" height="200">
  <!-- The Modal -->
  <div id="myModal" class="modal">
    <span class="close">×</span>
    <img class="modal-content" id="img01">
    <div id="caption"></div>
  </div>
  <script>
    // 获取模态窗口
    var modal = document.getElementById('myModal');

    // 获取图片模态框，alt 属性作为图片弹出中文本描述
    var img = document.getElementById('myImg');
    var modalImg = document.getElementById("img01");
    var captionText = document.getElementById("caption");

    img.onclick = function(){
        modal.style.display = "block";
        modalImg.src = this.src;
        modalImg.alt = this.alt;
        captionText.innerHTML = this.alt;
    }

    // 获取 <span> 元素，设置关闭模态框按钮
    var span = document.getElementsByClassName("close")[0];

    // 点击 <span> 元素上的 (x), 关闭模态框
    span.onclick = function() { 
        modal.style.display = "none";
    }
  </script>
</body>
</html>
